Blind stitch sewing machine



Jan. 24, 1939. s, BolGoN BLIND STITCH SEWING MACHINE Filed oct. 2o, 1957 s sheets-sheet 1 Jan. 24, 1939. s, BolGoN BLIND STITCH SEWING MACHINE Filed Oct. 20, 1957 3 SheetS-Shee ,2

rronnsy Jan; 24, 1939. s. BolGoN BLIND STITCH SEWING MACHINE 's sheets-sheet 5 Filed Oct. 20, 1957 Patented Jan. 24, 1939 UNITED STATES PATENT OFFICE 2,145,039 y BLIND STITCH SEWING MACHINE Samuel Boigon, Toronto, Ontario, lCanada Application october 2o, 1937, serial N. 170,064

4 claims. (C1. 11a-176) This inventionrelates to a blind stitch sewing machine. f

The objects of the invention, generally, are to improve on known blind stitch sewing machines. A-specic object of the invention is to provide such a machine capable of forming and stitching a seam in apiece of fabric so that the stitching does not show on one face or side of the fabric.

VAnother spe'cic object of the invention is to l0' provide means for so holding the fabric as it is fed to the needle, that the fabric will be rmly held 1in foldedv position when presented to the action of the needle and while being acted upon by the needle y Y -In'tliedrawingswherein like numerals of reference indicate corresponding parts in the various figures, Y

Figure l is a side elevation of a blind stitch sewing machine provided with my improvements, the work table beingV shown in dotted lines only; Figure 2 is a fragmentary, perspective View of 'Figure 1, but showing the Work table;

Figure 2A is a. view similar to Figure 2, but

Without the work table;` Figure 3 is a more or less diagrammatic view of a fragment of fabric, illustrating the stitching made by my present improved machine; Y

i Figui-e4 is a top plan view of the member upon which the fabric slides when being fed to the A needle; l

YFigure 5 is a side elevation of Figure 4;

Figure 6 is a fragmentary top plan view of Figure 2A;

l VFigure 7 is a detail 'of construction, showing more particularly the member co-operating with the member shownin Figures 4 and 5.

Thepresent invention is illustrated herein as embodied vin a blind stitch sewing machine of a well-known type, as manufactured by United States Blind Stitch Machine Corporation, more particularly a machine sold as model B-88.

Such a machine includes a stitch forming mechanism and a Work presenting mechanism which 'co-operate to form a line of single thread chain stitches and anchor said stitches in the opposite inner faces of a. piece of fabric. The space between the stitching may be folded so as to form, say, a pressed seam.

The invention is thus particularly useful in imparting a permanent crease to a trouser leg. A piece of fabric, which is to be made into ka trouser leg, is placed upside down and fed length- Wise through the machine, so that the stitches enter and emerge from the inner side only of the fabric and are, therefore, not exposed on the outer of needle penetrations.

face thereof, that is, on the outside of the trouser leg.

The stitching accomplished by such a machine is Vdiagramm'atically illustrated in Figure 3 of the drawings. For instance, the line of stitches includes a series of connected and uniformly spaced anchored needle loops b. Each loop b enters the inner face ofthe fabric and emerges from said face on each side of a fold F. Each loop b includes two portions, p and pl, which extend twice across the fold, and are disposed at an angle to each other, the portion p extending at right angles to the fold and the portion pl extending at asubstantial angle thereto. The degree of inclination depends on the length of the stitch, or, in other words, on the distance between points The portion pl is the closed end of the loop, and this loop is anchored -by the next formed needle thread loop. The

needle threadloops b enter and emerge on one side of the fold along lines which are fairly close to the fold, and are spacedequidistant therefrom, thus not only maintaining the fold, butr also maintaining the fold in a uniform manner throughout its length..

The machine includes a base or plate I0, a post or standard II, andan overhanging arm I2 supporting at its outer end a presser-foot I 3, a needle arm VI4 with curved needle I5, a looper mechanism M of which I6 is the looper proper, and feed mechanism of which I 'I is the feed dog. 'Ihe dog I'I is actuated by means such as is used in said model B-88 to impart to the dog a more or less oval trajectory such as permits of the dog engaging the fabric (not shown) to feed the same to ther'needle I5. The needle arm I4 is xedly mounted on one end of a shaft I8 to which is imparted an oscillatory motion by means such as is used in said model B-88. The presser-foot I3 has an elongated work-receiving opening I9, and its upper face is formed with needle guides 20 at right angles to the axis of the opening I9.

Disposed under the presser-foot so as to normally engage its underface is a support or guide 22 over which the fabric or Work may slide. The guide turns on a shaft 23 mounted on one end of a lever 24 pivotally mounted on the shaft 25 supported by the work table W, the lever having a crank 26 adapted to receive one end of a tensioned spring 21 whose other end is attached to a lug 28 of the work table W. The arrangement is such, therefore, that the guide 22 normally engages the underside of the presser plate, and permits of the .guide being pressed or moved bodily downwardly under the pressure of the feed dog as the same is on its rearward or feeding stroke. The guide is best shown in Figures 4 and 5. At its forward end, it is formed to provide a slot 21A, and is formed rearwardly of the slot with a recess 28; this recess accommodates the stitched fold in the fabric as the fold, once formed or stitched, moves rearwardly from the needle.

Disposed within the slot 21A and forwardly of the plane of the path of the needle is a member 29 having an upper curved edge recessed or grooved longitudinally as, at 3l. Thisrmember is fixed to the work table as on a non-rotatable shaft 30A. Co-operating with the groove is a resilientl or flexible member or rod 32, one end of the rod being fixed to a lug 33 from the presser platefandthe other or free end engagingand pressing into the groove or recess 3|. The member 29 and co-operating resilient nger 32 form means adapted for imparting two symmetrically formed and symmetrically directed folds to the fabric or work just aheadYK of the:` plane of ,the needlepath, the

work being thus presented to the action of the:

of the fold forming member 29. The lower face of the nger at its end normally lies slightly be'- low the upper venclofV the member 2Y9f-which is nearest the needle, so that the fingerwill operate to prevent the fabric. from substantially being pushed or drawn with. the needle` when thel latter is on its stitching stroke. For that purpose,

the plate 3S, from which the :lingerv 36A extends,- is journalled on a shaft 31 fixed at.A the end of an arm 38, which arm depends fromfa lug .39 secured to the head of the machine.v A springr 40 tensioned between the arm and'plate serves to urge.

the plate toward the presser-foot.

Fixed to the table W aforesaid, is aplate 9` which, in effect, operates as the-'work` table in lieu of the table W. The tablev W nowmerely forms a support for the plate; or work table 9. Formed into the rear edge ofthe plate- Seis a slot 20A disposed in alignment withthe.- axis of the resilient member 32. Thisaplate-is'also so. disposed above the table W, that itsupper faceis slightly above the rod 32 wherethe samejoins the lugA 33, all as best suggested in dotted lines in Figure l.

The slot 20A thus co-operateswith the rod- 32 toinitiate the fold in the fabricfwhich foldf is completed when the fabric lies between the rod and the member 29, just in advance of the path of the needle.

What I claim is:-

1. In a sewing machine for blind stitching, the combination of a presser-foot having an opening, a needle mounted to reciprocate above said opening, a fabric feeding mechanism, a member fixed substantially in the axis of said opening over which. the fabric' slides when acted upon, by said feeding mechanism, said member having` agroove, and a resilient member having one portion engaging: in said groove and forming with said first member means for imparting two symmetrically formed and symmetrically directed folds to the fabricY so -asto present two spaced folds into the path of said needle.

2. In a'sewing'machine for blind stitching, the combination of a presser-foot having an opening, a needle mounted to reciprocate above said opening,v a fabric feeding?mechanism;a` member fixed substantially in the axis of said openingfover which the fabricA slides whenv acted :upon by /said feeding mechanism, said mem-berhaving: a groove; a resilient member having one portionengaging in said groove and forming with said rst mem;`A berv meansl for imparting twoV symmetrically; formed and' symmetrically directed-folds tothe, fabric so asto present two spaced folds intowthe path of saidneedle, anda spring-pressed'fingerV adapted to engage at substantia-llyvits extremity the. fabric at a pointslightlyY clear ofgthe needlef pathwand yslightly to onefside-of saidfrst mem-- ber.

3. In a sewing machinev for blind stitchingthe combination,y of a presser-foot having aanneming.; a needle mounted to reciprocate above saidopen-z ing, ra fabric feeding mechanism, a member fixed substantially in'V the axis off; sia,id.o1fgez1ingl overwhich the fabric slides-when:acted,uponwbysaid;4

feeding mechanism, said rmember having a: groove, a resilient member havingone-portion engaging-7 in said groove and forming with said-first member means for imparting twoy symmetrically formedzand symmetricallyv directed folds vtortl'ie fabric so as to present-two spaced foldsinto the: path of said'needle, andr a-spring-.pressednger adapted to engageat substantially its extremity thefabric at a point slightlyclearbf the= needle path and slightly off the side of said first-mem ber whichzlies nearest thevpoint.j ofV the1 needle when'tlie sameisin penetrating position..

4. In a machine as set forth in claim: 11,; a." spring-pressed. finger adapted@ to engage the-fabriciat a point slightly clear vof the-needle Apath and. clear of saidy resilient member.

SAMUEL Bonsoir.l r

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